Type of production– a classification category distinguished based on the breadth of the range, regularity, stability and volume of products produced. Depending on the needs of a person, institution, industry or state, products are produced by enterprises in various quantities. Accordingly, production is conventionally divided into single, serial or mass.

The assignment of an enterprise (factory) or workshop to one or another type of production is called conditional because the simultaneous existence of different types is possible, i.e. individual products or parts can be manufactured in accordance with different principles: some - in a single order, others - in serial order, or some - in mass production, others - in serial order, etc. Thus, in heavy engineering enterprises characterized by single production of complex large-sized products (for example, walking excavators), small unified or standardized parts required for them in large quantities can be manufactured according to the principle of serial and even mass production.

Single (individual) production means the production of single copies of products according to unchanged drawings, which is not repeated or is repeated rarely, after an indefinite period of time.

Distinctive features of a single type of production are: homogeneity of manufactured products; lack of permanent assignment of certain products to workplaces; use of universal equipment, devices and tools; placement of equipment into similar groups; availability of highly qualified universal workers; large volume of manual operations; long duration of the production cycle, etc. This includes the production of experimental or unique samples of engineering products and any non-standard equipment.

Under serial Manufacturing refers to the production of products according to unchanging drawings in periodically repeating batches over a certain period of time.

Depending on the number of products in a batch, it is divided into: small-scale, serial And large-scale. This division is quite arbitrary. With the same number of products in a batch, of different sizes and complexity, production can be classified as different types. For example, making 25 roadheaders for the development of potassium ore deposits can be classified as medium-scale production, 25 heavy transport aircraft "Ruslan" - as large-scale production, and 25 small-sized lathes - as small-scale production. Approximately serial production is determined according to table. 1.1.

Table 1.1

Serial production

Serial production products are products produced in significant quantities: metal-cutting machines, pumps, compressors, etc. In this case, high-performance universal and specialized equipment is used; specialization of jobs to perform several assigned operations; universal, adjustable high-speed devices; universal and special tool. CNC machines, multi-purpose machines and flexible reconfigurable systems (FCS) are widely used. Serial production is also characterized by a small amount of manual operations, the presence of semi-skilled workers, a short production cycle, etc.

Under massive Manufacturing refers to the production of products according to unchanged drawings in large quantities and over a long period of time.

Mass-produced products are products of a narrow range and standard type, for example cars, bicycles, electric motors, sewing and washing machines, bearings, etc. Most workplaces perform only one assigned, repetitive task. Mass production is characterized by the following features: limited range of products; subject specialization of jobs; arrangement of equipment in the sequence of operations; use of high-performance automated and robotic equipment, special devices and tools; widespread use of transport devices for transferring workpieces along the production line; mechanization and automation of technical control; the presence of low-skilled workers; minimum production cycle duration, etc.

The type of production is determined by the coefficient of consolidation of operations TO z.o

Where Q – the number of operations performed or to be performed during a planning period of one month; P – the number of workers performing various operations.

The coefficient of consolidation of operations is one of the main characteristics of the type of production (GOST 3.1121–84). The value for mass production is TO z.o = 1, for large-scale production – 1–10, for serial production – 10–20. At single production TO z.o can be more than 40.

In mechanical engineering, there are two forms of production: non-flow and flow.

Non-flow refers to production in which its objects are in motion during the manufacturing process with varying durations of operations and breaks between them. This form is typical for single production.

In-line production is called production in which operations are assigned to certain workplaces, located in the order of their execution, and the production object is transferred from one workplace to another with a certain tact.

This is the most advanced form of organizing mass production from the point of view of minimizing costs. Automatic processing and assembly lines are built according to this principle. A feature of automatic production is the execution of operations without the direct participation of a worker or under his supervision and control. Flow production can also be non-automatic if the installation of workpieces and their removal after processing is performed by a worker.

To organize continuous production, the same or multiple productivity is required in all operations. On the line, processed workpieces or assembled units are released at a strictly defined time interval, called the release cycle.

Release stroke(min/piece) – time interval T between the release of two products or blanks of certain names, following one after another,

where Fd is the actual time fund in the planned period (month, day, shift), h; N– production program for the same period (number of products, pcs.).

Cycle– the calendar time interval from the beginning to the end of any repeating technological or production process, regardless of the number of simultaneously manufactured products.

A distinction is made between the manufacturing cycle of the product as a whole, individual assembly units and parts, and the performance of individual operations.

Each production has a certain production capacity, which is understood as the maximum possible output of products of the established nomenclature and quantity, which can be carried out over a certain period of time under the established operating mode.

In mechanical engineering there are three types of production: mass, serial and individual and two working methods: in-line and non-in-line.

Mass production characterized by a narrow range and large volume of products produced continuously over a long period of time. The main feature of mass production is not only the number of products produced, but also the performance of one constantly repeating operation assigned to them at most workplaces.

The production program in mass production makes it possible to narrowly specialize jobs and arrange equipment along the technological process in the form of production lines. The duration of operations at all workplaces is the same or a multiple of time and corresponds to the specified productivity.

Release cycle is the time interval through which products are periodically produced. It significantly influences the construction of the technological process, since it is necessary to bring the time of each operation to a time equal to or a multiple of the cycle, which is achieved by appropriately dividing the technological process into operations or duplicating equipment to obtain the required productivity.

To avoid interruptions in the operation of the production line, interoperational stocks (backlogs) of blanks or parts are provided at workplaces. Backlogs ensure continuity of production in the event of an unforeseen shutdown of individual equipment.

The flow organization of production ensures a significant reduction in the technological cycle, interoperational backlogs, backlogs and work in progress, the possibility of using high-performance equipment and a sharp reduction in labor intensity and cost of products, ease of planning and production management, the possibility complex automation production processes. With flow methods of work, working capital is reduced and the turnover of funds invested in production increases significantly.

Mass production characterized by a limited range of products manufactured in periodically repeating batches and a large production volume.

Equipment is widely used in large-scale production special purpose and aggregate machines. The equipment is located not by type of machine, but by the items being manufactured and, in some cases, in accordance with the work being performed. technological process.

Medium production production occupies an intermediate position between large- and small-scale production. The batch size in mass production is influenced by the annual production of products, the duration of the processing and adjustment process technological equipment. In small-scale production, the batch size is usually several units, in medium-scale production - several dozen, in large-scale production - several hundred parts. In electrical engineering and apparatus engineering, the word “series” has two meanings that should be distinguished: a number of machines of increasing power for the same purpose and the number of simultaneously launched into production of the same type of machines or devices. Small-scale production according to your own technological features approaches unity.

Single production characterized by a wide range of manufactured products and a small volume of their output. A characteristic feature unit production is carried out at workplaces various operations. Unit production products are machines and devices that are manufactured according to individual orders that require the implementation of special requirements. These also include prototypes.

In single production, electrical machines and devices of a wide range are produced in relatively small quantities and often in a single copy, so it must be universal and flexible to perform various tasks. In single production, quickly adjustable equipment is used, which allows you to switch from the manufacture of one product to another with minimal loss of time. Such equipment includes computer-controlled machines, automated warehouses, computer-controlled, flexible automated cells, sections, etc.

Universal equipment in single production is used only in enterprises built earlier.

Some technological methods that arose in mass production are used not only in serial, but also in individual production. This is facilitated by the unification and standardization of products and specialization of production.

Assembly of electrical machines and devices is the final technological process in which individual parts and assembly units are combined into a finished product. Main organizational forms the assemblies are stationary and movable.

For stationary assembly the product is completely assembled at one workplace. All parts and assemblies required for assembly are supplied to workplace. This assembly is used in single and serial production and is carried out in a concentrated or differentiated manner. With the concentrated method, the assembly process is not divided into operations and the entire assembly (from start to finish) is performed by a worker or team, but with a differentiated method, the assembly process is divided into operations, each of which is performed by a worker or team.

For moving assembly the product moves from one workplace to another. Workstations are equipped with the necessary assembly tools and devices; on each of them, one operation is performed. The movable form of assembly is used in large-scale and mass production and is carried out only in a differentiated way. This form of assembly is more progressive because it allows assemblers to specialize in certain operations, resulting in increased labor productivity.

During the production process, the assembly object must sequentially move from one workplace to another along the flow (such movement of the assembled product is usually carried out by conveyors). Continuity of the process during continuous assembly is achieved due to the equality or multiple of the execution time of operations at all workstations of the assembly line, i.e., the duration of any assembly operation on the assembly line must be equal to or a multiple of the release cycle.

The assembly cycle on the conveyor is the planning beginning for organizing the work of not only the assembly department, but also all the procurement and auxiliary workshops of the plant.

With a wide range and small quantities of manufactured products Frequent reconfigurations of equipment are required, which reduce its productivity. To reduce the labor intensity of manufactured products, flexible automated systems have been developed in recent years based on automated equipment and electronics. production systems(GAPS), allowing the production of individual parts and products of various designs without reconfiguring equipment. The number of products produced at GAPS is set during its development.

Depending on the designs and overall dimensions of electrical machines and devices, different assembly processes . The choice of technological assembly process, the order of operations and equipment is determined by the design, volume of production and the degree of their unification, as well as the specific conditions existing at the plant.

Department of Technology and Organization engineering production

Discipline

"Technological fundamentals of mechanical engineering" (VOL)

Lecture notes

E.P. Vyskrebentsev

For students of the specialty "Metallurgical Equipment"

3rd year full-time study

4th year distance learning

Main

1. Kovshov A.N. Mechanical engineering technology: textbook for universities. – M.: Mechanical Engineering, 1987

Additional.

2. Gorbatsevich A.F., Shkred V.A. Course design in mechanical engineering technology. – Minsk: Higher School, 1985.

3. Vorobyov A.N. Mechanical engineering technology and machine repair: Textbook. – M.: Higher School, 1981.

4. Korsakov V.S. Mechanical engineering technology. – M.: Mashinostroeniya, 1987.

5. Handbook of mechanical engineering technologist: in 2 books. under. ed. Kosilova A. G. – 3rd ed. – M.: Mechanical Engineering, 1985.

6. Balabanov A.N. A short reference book for a mechanical engineering technologist. – M.:

Ed. standard. 1992.

INTRODUCTION 5

1 TYPES OF PRODUCTION, FORMS OF ORGANIZATION AND TYPES

TECHNOLOGICAL PROCESSES 6

1.1 Types of production 6

1.2 Types of technological processes 9

1.3 Structure of the technological process and its main

characteristics 11

1.3.1 Process characteristics 15

1.4 Labor intensity of the technological operation 16

1.5 Basic principles technological design 21

2 PRECISION MACHINING 23

2.1 Accuracy and its determining factors 23

3 FUNDAMENTALS OF BASEMENT AND BLANKET BASE 27

3.1 Fastening error ε з, 36

3.2 Workpiece position error ε pr caused by

inaccuracy of device 37

3.3 Positioning the workpiece in fixture 38

4 SURFACE QUALITY OF MACHINE PARTS AND

BLANKET 41

4.1 Influence of technological factors on the value

roughness 41

4.2 Methods for measuring and assessing surface quality 46

5 PRODUCTION OF MACHINE PARTS 49

5.1 Selection of the initial workpiece and methods of its production 49

5.2 Determination of machining allowances 51

6 MAIN STAGES OF TECHNOLOGICAL DESIGN

MECHANICAL PROCESSES 60

6.1 General provisions development of technological

processes 60

6.2 Selection of technological equipment 63

6.Z. Selection of technological equipment 64

6.4. Selection of controls 65

6.5. Forms of organization of technological processes and their

development 65

6.6. Development of group technological processes 67

6.7. Development of standard technological processes 70

7 TECHNOLOGY FOR MANUFACTURING TYPICAL PARTS 72

7.1 Shaft production technology 72

7.2 Technology for the production of body parts 82

7.2.1 Technological route for processing workpieces

buildings 84

7.3 Cylinder production technology 92

7.4 Machining gears 94

7.4.1 Design features and technical requirements for teeth

wheels 94

7.4.2 Machining blanks of gear wheels with a central hole. 95

7.4.3 Tooth cutting 97

7.4.4 Manufacturing of large gears 100

7.4.5 Processing of workpieces before cutting teeth 101

7.5 Lever manufacturing technology 102

8. TECHNOLOGICAL ASSEMBLY PROCESSES 111

INTRODUCTION

Mechanical engineering technology is a science that studies the patterns of machine manufacturing processes in order to use these patterns to ensure the production of machines of a given quality, in the quantity established by the production program and at the lowest economic costs.

Mechanical engineering technology has evolved with the development large industry, accumulating appropriate methods and techniques for making machines. In the past, mechanical engineering technology was most developed in weapons workshops and factories, where weapons were manufactured in large quantities.

Thus, at the Tula Arms Factory back in 1761, for the first time in the world, the production of interchangeable parts and their control using calibers was developed and introduced.

Mechanical engineering technology was created by the works of Russian scientists: A.P. Sokolovsky, B.S. Balakshina, V.M. Kovana, B.C. Korsakova and others,

Mechanical engineering technology includes the following areas of production: casting technology; pressure treatment technology; welding technology; technology machining; machine assembly technology, i.e. mechanical engineering technology covers all stages of the process of manufacturing engineering products.

However, mechanical engineering technology is usually understood as a scientific discipline that studies primarily the processes of mechanical processing of workpieces and assembly of machines and, incidentally, touches on the issues of choosing workpieces and methods of their manufacture. This is explained by the fact that in mechanical engineering, given shapes of parts with the required accuracy and quality of their surfaces are achieved mainly by mechanical processing. The complexity of the machining process and the physical nature of the phenomena occurring during this process is caused by the difficulty of studying the entire complex of issues within one technological discipline and led to the formation of several such disciplines: metal cutting; cutting tools; metal cutting machines; design of devices; design of machine-building workshops and factories; interchangeability, standardization and technical measurements; technology of construction materials; automation and mechanization of technological processes, etc.

1 TYPES OF PRODUCTION, FORMS OF ORGANIZATION AND TYPES

TECHNOLOGICAL PROCESSES

1.1 Types of production

Type of production- classification category of production, distinguished on the basis of breadth of product range, regularity, stability and volume of product output.

Product output volume - the number of products of a certain name, standard size and design manufactured or repaired by an association, enterprise or its division during a planned time interval.

The following types of production are implemented: single; serial; massive. One of the main characteristics of the type of production is the coefficient of consolidation of operations. Operation consolidation coefficient is the ratio of the number of all various technological operations performed or to be performed during the month to the number of jobs.

Single production - production characterized by a wide range of manufactured or repaired products and a small volume of product output.

In single production, products are manufactured in single copies, varying in design or size, and the repeatability of these products is rare or completely absent (turbine construction, shipbuilding). In this type of production, as a rule, universal equipment, fixtures and measuring instruments are used, the workers are highly qualified, assembly is carried out using fitting work, i.e. on site, etc. Machines are located based on the uniformity of processing, i.e. . sections of machines are created designed for one type of processing - turning, planing, milling, etc.

Transaction consolidation ratio > 40.

Mass production - production characterized by a limited range of products manufactured or repaired in periodically repeating production batches.

Depending on the number of products in a batch or series and the value of the consolidation coefficient of operations, small-scale, medium-scale and large-scale production are distinguished.

The coefficient of consolidation of operations in accordance with the standard is taken equal to:

a) for small-scale production - over 20 to 40 inclusive;

b) for medium-scale production - over 10 to 20 inclusive;

c) for large-scale production - over 1 to 10 inclusive.

The main features of mass production: machines are used of various types: universal, specialized, special, automated; personnel of various qualifications;

work can be done on configured machines; both markings and special devices are used; assembly without fitting, etc.

The equipment is located in accordance with the subject form of work organization.

Machines are arranged in a sequence of processing operations for one or more parts that require the same order of operations. In the same sequence, obviously, the movement of parts (the so-called object-closed areas) is also formed. Processing of blanks is carried out in batches. In this case, the execution time of operations on individual machines may not be consistent with the time of operations on other machines.

Manufactured parts are stored at the machines during operation and then transported as a whole batch.

Mass production - production characterized by a narrow range and large volume of output of products that are continuously manufactured or repaired over a long period of time.

The coefficient of consolidation of operations for mass production is taken equal to one.

In mechanical engineering there are three types of production: mass, serial, single(GOST 14.004-83). The ratio of the number of all various technological operations O performed or to be performed during the month to the number of jobs P is called transaction consolidation coefficient

The coefficient of consolidation of operations is one of the main characteristics of the type of production.

With the variable-flow method, each machine of a line (section) is assigned several operations for technologically similar parts that are put into production alternately. For a certain period of time (usually several shifts), the line processes workpieces of a certain standard size. Then, the line is reconfigured to process workpieces of a different standard size of the station assigned to this line, for example, devices on variable flow lines are permanently attached to the technological equipment. The devices are designed so that they can process workpieces of any standard size in a fixed group. This significantly reduces the line changeover time, which is usually performed during breaks between shifts. By placing the equipment along the process flow, we obtain the movement of parts from one workplace to another, although intermittent (in batches), but in-line (direct flow). By passing replaceable batches of parts through a group of work stations (sequence of technological equipment), we obtain continuous-flow (within one batch) production with piecemeal transfer of parts from one workstation to another. To increase the equipment load in serial production, multi-product production lines are used (variable-flow, group, subject-closed sections of lines).

During group processing, at each workstation, the lines simultaneously perform several operations of different technological processes. This is ensured by the use of special multi-seat devices. With group processing, equipment utilization increases, and the line operates without equipment readjustment. The number of parts in a group is usually 2...8. Variable-precision and group processing (assembly) is performed on conventional and automatic lines.

For processing structurally and technologically similar workpieces, subject-closed sections are used. TP processing of these workpieces have the same structure, homogeneous operations and the same sequence of their execution and are based on a generalization of TP for manufacturing parts with similar design and technological parameters.

The flow method of work provides a significant reduction (tens of times) in the production cycle, interoperational backlogs and work in progress, the possibility of using high-performance equipment, reducing the labor intensity of manufacturing products, and ease of production management.

In serial production, when constructing technological operations, both differentiation and concentration of technological transitions are used. The structure of the operation is formed as a result of a compromise of these principles, taking into account specific conditions and methods of work. The use of the flow method in mass production requires, as a rule, when constructing operations, the priority of differentiating transitions.

For small production volumes, frequent changes in manufactured products, and the impossibility of using a precise method, use non-flow method work. This method is used in mass production conditions; it is most typical for small-scale and individual production. With the non-flow method of work, operations are not strictly assigned to specific workplaces, the duration of operations is not synchronized according to the production cycle, and backlogs of blanks (assembly units) necessary to ensure the loading of workplaces are created at the workplaces. With a non-linear method of work, they strive to implement the maximum technological impact on the subject of labor at each workplace, reduce the number of operations in technological processes, and build technological operations based on the concentration of transitions. The degree of concentration increases as the volume of release decreases.

The characteristics of production are reflected in the decisions made during the technological preparation of production.

In mechanical engineering, there are three main types of production: single (individual), serial and mass, and two methods of work: flow and non-line.

Each type of production has its own methods of preparation and planning. They also differ in the form of labor organization, the degree of detail in the development of technological processes, the organization of repairs, etc.

Single(individual) is a production in which the product is made in one or several copies; As a rule, these products are almost never re-manufactured. Such production exists in heavy and chemical engineering, shipbuilding, etc.

In single production, universal machines, universal fixtures and normal tools are used to process a variety of parts. Special tools and special devices are almost never used, since their production requires high costs. Installation and alignment of workpieces on machines is carried out using markings and universal measuring instruments. The manufacturing accuracy of the part is also controlled by universal measuring instruments - caliper tools, micrometers, indicators, etc.

The qualifications of workers in single production are usually high, but labor productivity is much lower, and the cost of the part is higher than in serial and mass production.

In mechanical engineering, the most widely used serial production in which products are produced in batches or series of various sizes. Depending on the size of the batches and frequency of repetition throughout the year, they are distinguished small-scale , mid-production And large-scale production. The main difference between mass production and individual production is the less diverse range of products manufactured at each workplace and the periodic repetition of batches of products.

In mass production, the percentage of universal machines is decreasing, but increasing specific gravity specialized and special machines. Machines such as turrets, multi-cutting lathes, and in large-scale production also semi-automatic and automatic lathes are widely used. The specialization of machine tools allows the use of specialized and special devices and cutting tools, which ensure increased labor productivity and reduced product costs. Limit gauges are often used to control the processing accuracy of parts.

Serial production is characterized by a differentiated technological process for manufacturing parts. It is divided into a number of small-scale operations performed on various machines. Operations requiring more than one installation are not usually encountered in series production. The qualifications of workers are significantly lower than in individual ones, and labor productivity is higher.

Batch production is common in all industries.

Mass production is characterized by a large number of manufactured products, which allows each workplace to perform only one, constantly repeating operation.

In mass production, highly specialized automatic machines, special devices and cutting tools are widely used. The dimensions of the manufactured part are controlled using special devices, often during processing. Depending on the equipment used, the technological process of machining is divided into a number of small operations carried out on separate special machines, or involves performing many transitions on multi-spindle machines, multi-position aggregate machines, etc.

Mass production ensures the most economical processing of products. This type of production is widespread in the automobile and tractor industries, in factories producing agricultural equipment, motorcycles and a number of other products. The type of production depends on the given program and the labor intensity of manufacturing the product and is determined by the production cycle and the serialization ratio.

Under release stroke refers to the time interval between the release of two successive machines and their assembly units - parts or blanks. When designing technological processes of mechanical processing, the value of the release stroke is determined by the formula:

Where F d– the actual annual operating time of the equipment in one

shift, in hours; m– number of work shifts; N– annual parts production program, pcs. The serialization coefficient shows the number of different operations assigned to one machine and is calculated using the formula:

Where τ in– parts release cycle; T pcs– average piece time for part processing operations.

To determine T pcs, it is necessary to make an enlarged calculation or take time for similar operations performed at the base plants.

For mass production K ser < 2, для крупносерийного Xer from 2 to 10, for medium-scale production from 10 to 20 and small-scale production Xer >20.

Thus, knowing the value of the production cycle and the serialization factor, it is possible to preliminarily determine the type of production.

At in-line In production, machining operations are assigned to certain workplaces, which are arranged in the order prescribed by the technological process, and the workpiece is transferred from one operation to another without significant delays.

Non-flow production is one in which the parts being manufactured are in motion during processing with breaks of varying durations, i.e. the processing process is carried out with a changing tact value.